Method and apparatus for distributing parasiticides



Nov. 26, 1940. R. B.v ARNOLD kMETHOD AND APPARATqs FORDISTRIBUTING PARASITIQIDES Filed June 3,'1959 8 Sheets-Sheet l @f/1m V414 ATTORNEYS Nov. 26, 1940. R.B. ARNOLD 2,222,598"

METHOD AND APPARATUS` FORl DISTRIBUTING PARASITICIDES Filed June 3', 1939 8 Sheets-Sheet A2 www ATTORNEYS N0v.26,1940.A R B AF'QNOL-D 2,222,598

METHOD AND APPARATUS FOR DISTRIBUTING PARASITICIDES Filed June 3, 1939l 8 Sheets-Sheet 3 VEN OR. v

BY/ a d? (WM Nov. 26, 1940.

R. B. ARNOLDr METHOD AND APPARATUS FOR DISTRIBUTING PARASITICIDES s sheets-sheet 4 Filed Jun@` s, 193.9

l i g I l l I i i |I i I2 .1!....LJ

i i l INVENToR Wg. www BY Jaun/f6 m MM' 0% ATTORNEYS R. B. ARNOLD 2,222,598

METHOD AND APPARATUS FOR DISTRIBUTING PARASITICIDES Nov. 26, 1940.

Filed June 5, 1959 8 Sheets-Sheet 5 ATTORNEYS Nov. 2.6, 1940. RB. ARNOLD METHOD AND APPARATUS FOR DISTRIBUTING PARASITICIDES 8 She'etS-Sheet 6 w INVENToR @QW/Z ATTORNEYS 26, 1940. R. aARNoLD 2.222,598

METHOD AND`APPARATUS FOR DISTRIBUTING PARASITICIDES 8 sheets-sheet v Filed June 3, 1939 o l I MLM-1 ATTORN S Nov. 26, 1940. R. B.ARNoLD METHOD AND APPARATUS FOR DISTRIBUTING PARASITICIDES Filed June..5, l9\39 8 Sheets-Sheet 8 INVENTOR /LZ'I @Mr/M A ORNEYS Patented Nov. 26, 1940 UNITED f s'rArEs METHOD AND APPARATUS Foa Dls- 'rmnU'rmG PAnAsmccmEs Robert B. Arnold, Stonewall Courts, Va.,'assignor to Tobacco By-Products and Chemical Corporation, Louisville, Ky., a corporation of Delay Application June 3, 1939, serial No. 277,147

1s claims. (C1. 4s14s This invention relates to methods of and apparatus for the application of parasiticides to eld plants, as distinguished from plants growing in greenhouses or other enclosed spaces.

Broadly considered the invention may be carried out' when employing any parasiticidal dusts or fumes which will check or exterminate plant fungi, bacteria, or insects.

More specifically considered the method and lo apparatus are particularly suitable for the application, to el'd plants, of parasiticides of a volatilizable nature such as nicotine, neonicotine and anabasine where the volatilizable parasiticide is converted into a gaseous state and then used to form a fumigating atmosphere in contact with the plants, or to form a fresh parasiticidal dust which is then 4brought into contact with the plants. Furthermore, both such methods may-be employed simultaneously.

In the description hereinafter given the method and apparatus constituting the invention will be set forth in connection withl nicotine as the volatilizable parasiticide, but it is to be. understood that other parasiticides resembling nicotine, such,

5 for example, as neonicotine and anabasine may be substituted for the nicotine.

The lethal eect on plant parasites of fumes containing nicotine as the parasiticide, is dependent partly on the concentration of the nicotine in the fumes and partly on the period of exposure of the parasites thereto. Hence, an increase in the nicotine concentration permits a decrease-in the period of treatment. In fact, fumes of appropriate nicotine strength will kill the parasites almost instantly, and Where fumes of sufcient nicotine concentration can be obtained and maintained around the plant the results are highly satisfactory against insects sensitive to nicotine because the fumes readily spread to reach all parts of the plant and thereby come in contact with all the parasites on such plants. This is the great advantage of fumigation as compared'with spraying or dusting.I When either the concentration of nicotine in the fumes or the period of exposure of the parasites to the fumes is inade-Y quate, some of the parasites may be killed and the others adversely affected but in most cases a suicient proportion will revive when the fumes are removed and thereby reinfest the plants, thus rendering the treatment ineiective and uneconomical. For commercial practicability it 1s necessary that all or substantially all of the parasites be killed.

Nicotine fume treatment has therefore been specially e'ective in enclosed spaces such as green houses and the like where appreciable inflow' of the outside atmosphere is readily avoided and there is plenty of time tovbuild up a strong concentration of the nicotine in the fumes. Entirely different, problems are presented in the 5 treatment of plants growing .in the open. Such treatment is carried out beneath movable tents, canopies or aprons and commercial requirements make it necessary to move such temporary enclosures from one treatment location to another as rapidly as possible to avoid prohibitive expense. In the treatment of held. crops it is usual to employ a continuously movable enclosure such as a canopy or apron drawn behind a truck and covering a substantial area of relatively low-growing plants, a system that is especially adapted for the destruction of the pea Aphis and similar parasites. With such an arrangement it has heretofore been necessary, in order to obtain the requisite duration of treatment, to employ rela- 20 tively long and cumbersome canopies or aprons with consequent diiiiculties in supporting and manipulating the aprons as well as an increased tendency to damage the plants. Apparatus of this escape beneath the apr'on, the introduction of the fumes into the space beneath the apron creating a pressure that tends to increase lsuch leakage.

A general purpose of the, invention is to provide an improved method and apparatus which 30 will insure the application to plantsin the eld of fumes having a concentration of nicotine or other parasiticides substantially higher' than has beenpracticablyobtainablebypriorsystems. This result is attained byrecirculating thefumes or dust 35 charged air between the space beneath the apron and a supply source such a blower,and adding sufficient nicotine dustor the like to thecirculating stream to maintain the desired high fume concentration. In this way the pressure beneath the 40 apron is reduced or maintained more nearly normal, as compared with prior methods, and there'- by there is a corresponding decrease in the'ten dency to leakage. Furthermore, such air as may leak inwardly into the space beneath the apron 45 will be Withdrawn from such space with the circulating `stream and charged with fumes before return to the zone of action. I

When the system is employed with a continuously traveling canopy the fumes are advan- 50 tageously discharged beneath the forward part of the canopy where the tendency to inward leakage of air isfgreater, and are withdrawn at a point toward the rear of the canopy wherether is a greater tendency to outward leakage of the 55 fumes. The recirculation system is likewise arranged to improve the uniform dissemination of the fumes around the plants, creating a current beneath the anopy which may readily be directed into and through the plant growth, increasing the thoroughness with which the fumes reach the lower sides and more remote portions of the plant surfaces.

While the nicotine fumes alone are effective, their action is assisted when the nicotine is carried by finely divided material which will adhere to the plants. A feature of the invention is the provision of a system by which the nicotine is eiiiciently applied -to the plants in this manner. This system is advantageously combined with the fume treatment and recirculation system, the latter serving to avoid waste of powder that does not adhere to the plants.

Another characteristic of the invention, designed to enhance the effective strength of the nicotine at the point of application, includes the incorporation of the nicotine with a carrier such as lime immediately before application to the plants. ASpecically, the nicotine is advantageously combined with the pulverized lime in the space beneath the apron or other enclosure immediately prior to its application to the plants. The invention includes an improved arrangement for combining the nicotine and the carrier powder and distributing the resulting nicotine dust through the .plant growth. It has been found that with this system highly lethal nicotine concentrations beneath the apron can beobtained, and that the nascent nicotine dust is especially effective.

'I'he nicotine in liquid f orm is advantageously gasied by heat before use. In the best embodiment now contemplated thenicotine is applied to the carrier powder in heated gaseous form and novel means is provided for this purpose. In this embodiment the nicotine is conveniently gasied by heat from the exhaust of an internal combustion engine, and a feature of the invention is the arrangement of the fumigating apparatus as a separate unit, adapted for mounting on a tractive vehicle such as a truck,l and including a. 4separate engine which is advantageously employed to operate a. recirculation blower and to provide the necessary exhaust heat for gasifying the nicotine. This construc. tion permits better control of the system and, in particular, improved gasification of the nicotine as compared to an arrangement employing heat from the truck engine exhaust for the purpose, since the heat generated by the independentgengine is not dependent on truck speed.

It has been found that when nicotine of a high degree of purity is employed, a tendency toward decomposition when the nicotine is gasined is counteracted by the incorporation of a suitable liquid hydrocarbon having a boiling point below that of nicotine. This system is disclosed in the patent to Arnold, No. 2,120,225 and in Arnold application Serial No. 121,447, of which this application is a continuation in part. The invention likewise includes the combination of the hydrocarbon and nicotine with the dustin powder.

The system set forth herein permits the effective use of a much shorter apron, due to th'e higher concentration of effective nicotine and the more efiicient distribution thereof, providing a lethal effect in a much shorter time than that required by previous systems. Furthermore, the incorpora-tion of the nicotine in dust adherent to the plants provides insecticidal action after the apron' has passed beyond the treated plants.

An improved arrangement for supporting a traveling canopy and for distributing the nicotine and powder beneath the canopy has been provided, and includes means for collapsing portions of the structure extending beyond the truck.

Other objects and advantages of the invention will appear from the following description considered in connection with the accompanying drawings in which Fig. l is a side elevation of the forward portion of a plant fumigating unit mounted on the rear part of an automobile truck body;

Fig. 1a is a similar view in continuation of Fig. l extending to the left thereof and showing the remaining rearward portion of the unit;

Fig. 2 is a rear elevation of the right hand half of said unit with the apron removed;

Fig. 2a is a similar elevation of the left hand half of the unit in continuation of Fig. 2, showing the apron in place;

Fig. 3 is a plan view of the arrangement shown in Fig. 1, omitting portions extending laterally beyond the truck;

Fig. 4 is a view similar to Fig. 1 with parts broken away and showing a modified mixing and distributing arrangement;

Fig. 5 is an enlarged elevation of the powder feeding system with parts broken away;

Fig. 6 is an enlarged detail of the recirculation system suction inlet, baffle and associated parts;

Fig. 'I is a longitudinal vertical sectional view through the nicotine supply tank and associated gauge;

Fig. 8 is a vertical section through the nicotine supply pump;

Fig. 9 is an enlarged side elevation showing one form of separate Joint in the powder distributor;

Fig. 10 is an enlarged fragmentary end elevation of a distributor of the type employed in the construction shown in Figs. 1 and 4;

Fig. 11 is a view similar to Fig. 9 showing another arrangement for shifting the outer end portion of the powder distributor, including a hinge connection:

Fig. 12 is a transverse section through the distributor on line I2--I2, Fig. 11, and

Fig. 13 is a rear `elevation of a modified form of unit including connections to a stationary canopy. I

Apparatus embodying the invention includes in general an apron, means for supplying nicotine fumes to the space beneath the apron, a recirculating system, a nicotine supply, a nicotine gaslfying arrangement and a powder feed apparatus. The illustrated embodiment is mounted on the rear portion of an automobile truck body'20 and includes a frame 2i of structural steel members resting on truck body 2D and carrying an internal combustion engine 22,

.a centrifugal blower 23 driven by the shaft of dfi port 33 connected to nicotine supply pipe 3|, and a discharge port 34. Piston 35 is reciprocated in cylinder 32 by suitable mechanism, such as piston rod 36 pivoted to piston 35 and to roller 31 which travels along a suitable edge cam 38. The track of cam 38 is generally square in contour and roller 31 is maintained in engagement with the track by a rocking frame 39 including arm 48 on which roller 31 is rotatably mounted and arm 4I carrying roller 4.2 engaging cam 38 at a point offset 135 around the axis of cam 38 so that roller 42 will engage a corner of the cam track when'roller 31 is at the middle of one of the sides, and vice versa, this arrangement being known and adapted to produce positive outward and inward movement of roller 31 and parts connected thereto. Frame 39 is pivotally mounted on rock-shaft 54 carried by hollow casing 55 enclosing the drive mechanism described and is shown as unitary with cylinder 32.

A second piston 35a is reciprocably mounted in cylinder 32 and is yieldably held in predetermined position, as by spring 43 bearing against piston 35a and cap 44 threaded on the upper end of cylinder 32 and provided with a seat 45 engaged by flange 46 on piston 35a.

At the beginning of the feed stroke piston 35 is located below inlet port 33 vand piston 435a below discharge port 34, with flange 46' resting on seat 45. The space between pistons v35 and 35a determines the volume of liquid fed at each stroke of the pump and may be varied by changing the lowermost position of piston 35a, readily accomplished in the illustrated construction by screwing cap 44 along cylinder 32 to the required point. The upward stroke of piston 35 will raise piston 35a against spring 43 by pressure of the liquid against piston 35a until' discharge port 34 is cleared, the continued movement of piston 35 expelling thezliquid through said port until the top of the stroke is reached. During the return stroke of piston 35 the upper piston 35a will rst return to its place as determined by the position of seat 45, and continued movement of piston 35 will fill the cylinder with theY requisite amount of liquid entering through port 33.

In View of the importance of measuring accurately the amount of nicotine supplied to the system, a convenient and practical arrangement for determining the amount fed by the pump is provided to facilitate accurate adjustment of the pump capaci-ty. In this arrangement the pump discharge pipe 41" is connected throughv threeway cock 48 either to the nicotine feed line 49 or through connecting pipe 56 toa calibrated glass sight gauge 5I in which the rate at which the nicotine is fed by pump 26 can be observed as the gauge is filled by the pump, particularly in relation to the distance traveled by the truck when the pump 26 is driven from the truck wheel as hereinafter set forth. Connecting pipe 50 is provided with a three-way cock 52 connected to a discharge pipe 53 extending into tank 25, cock 52 being arranged so that the nicotine from pump 26 may be discharged either into gauge 5l or tank 25 and nicotine accumulated in gauge 5I may be drained into said tank. A suitable arrangement for driving pump 26 is provided so that in treating eld crops the pump will be accurately actuated or controlled in conformity with the rate of truck travel to assure the application of the same quantity of fumigant to a given area regardless of variations in the speed of the truck. In the best embodiment ci the invention this is accomplished by driving pump 26 from truck wheel 56. In the form illustrated the driving arrangement includes a pulley 51 mounted coaxially with wheel 56 on a tubular extension 58 bolted to the Wheel. Belt 59 passes around wheel pulley 51 and drive pulley 66 mounted on driven shaft 6I suitably journaled on frame 2| and carrying drive pulley 62 which by means of belt 63 drives pump pulley 64 mounted on pump shaft 65 (Fig. 8) journaled in pump casing 55 and carrying cam 38 fixed thereto. A suitable clutch 66 operated by handle 61 may be interposed in shaft 6I between drive pulley 60 and the remaining pulleys on said shaft. Belt 59 is maintained at proper tension as by tension' roller 68 bearing against the belt and mounted on arm 69 pivoted on shaft 6I and pressed toward Suitabl'e means is provided for distributing the nicotine to the area under treatment, this including means for gasifying the nicotine before. application to the plant growth. Such gasication is best carried out under the conditions set forth in Arnold Patent 2,120,225 and Arnold application, Serial No. 121,447. In the best embodiment now contemplated and illustrated herein this is accomplished by utilizingthe exhaust from internal combustion engine 22 to gasify the nicotine and propel the gaseous nicotine to a suitable distribution apparatus. In order to obtain the gasification of the nicotine it is necessary to heat the nicotine to |a temperature above its boiling point, which in practice is in the neighborhood of 478 F., but depends somewhat upon the pressure at the point of vaporization. In order to obtain the proper conditions the engine exhaust 15, although it may bev of the -usual diameter, for example 1%, inches, may have a portion, for example, about two or three feet of its length, enlarged in diameter, to serve as a vaporizing chamber. In usual practice this enlarged diameter maybe 11/2 inches. Pipe 15 is furthermore enclosed in a relatively heavy thermal insulating jacket 16, the pipe diameter and insulation being designed to produce the necessary temperature for nicotine gasification. Nicotine feed line 49 discharges the nicotine into exhaust pipe 15 at a point suiiiciently spaced from; the outlet of the latter pipe to assure complete nicotine gasification in the pipe. A suitable thermometer 11 is associated with pipe 15 toward its discharge end to permit ready observation of the temperature in thepipe as a guide to adjustment thereof, as by Varying the speed of the engine, or retardation of the spark of engine 22, or supplying additional heat. Also the temperature attainable may bev determined by the thickness and kind of insulation used for the jacket 16. .It is important in this invention to gasify the nicotine where it mixes with the exhaust gases as distinguished from suspensions of nicotine in gas below such temperature, sometimes referred to asvapor. The nicotine fumes referred to herein are in general composed predominately of nicotine in gaseous phase up to the point of discharge, becoming a nely dispersed vapor when discharged.

Pipe 15 discharges into a suitable nicotine distributor; comprising in general a pipe 18 extending transversely across the .area to be treated and provided with a plurality of nozzles 19 arranged to provide a substantially continuous flow of nicotine across saidarea. In the best embodiment of the invention, the pipe 18 is arranged so that the lateral portions thereof extending beyond the truck body may be collapsed when not in use. A suitableconstruction for this purpose includes a central pipe section connected to pipe 15 and connected by means of hangers 8| to the bed frame 2|. Pipe section 80 communicates at its ends with lateral pipe sections 82 through swivel connections 83 arranged to permit sections 82 to be swung forwardly to positions in longitudinal alignment with the truck body 20.

A suitable arrangement is provided for recirculating the nicotine fumes. When the invention is applied to a continuously traveling unit this arrangement includes means for withdrawing the fumes from the rearward -portion of the area under treatment and returning them to the forward portion of such area. In the construction illustrated a recirculation pipe system is connected to centrifugal blower 23 driven by engine 22 and includes a return pipe 84 having downwardly directed suction inlets 85 connected through cross pipe sections 86 to the rear section 61 of return pipe 84 which is laterally deflected and connects withthe main body 88 of return pipe 84 extending alongk one side of the frame 2| to front pipe section 89 which extends transversely to the inlet of blower 23. 'I'he rear section 81 and end sections 66 of pipe 84 may 'conveniently be mounted on an extension frame 90 bolted to the main frame 2|, and may be separable from main body 88 to permit the removal of portions of the unit extending substantially to the rear of truck body 20, if desired.

The recirculated fumes are fed4 to the treated area through feed pipe 93 extending rearwardly along frame 20 from the outlet aofV fan 23 and having a down-turned rear end section 94 discharging into a distributor 95 extending transversely across the area under treatment. Distributor 95 is of suitable contour and construction to provide a substantially uniform discharge of the fumes across the entire treated area and desirably comprises a suitable proportioned transverse passage 96 (Fig. 12) having a substantially continuous restricted discharge opening or slot 91 extending along the' lower part of passage 96.

The portions of the distributor 95 extending laterally beyond truck body 20 are arranged so that they may be removed or collapsed when not in operation. In the arrangement illustrated distributor 95 includes a central section 98 communieatingwith end section 94 of feed pipe 93 and not substantially greater in total transverse length than the width of the truck body 20. Lateral sections 99 are shiftably connected to central section 98 and are reduced in cross section toward their outer ends to reduce the arca of passage 96 in proportion to the rate of discharge of the fumes, thereby maintaining a uniform flow through outlet 91. Distributor 95 may be of hollow sheet metal construction with the lower portions of the side walls converging downwardly to outlet 91. Various contours may be employed, the constructions shown in Figs. 1-10 being generally pentagonal, while that illustrated in Figs. 11 and 12 is triangular, each including relatively flat walls defining passage 96 and converging toward the outer ends of the lateral sections 99.

Suitable bailles |0| in passage 96 in alignment with the discharge from section 94 of the feed pipe and extending downwardly and outwardly from the center line of said section, may be provided to assist in uniform distribution of the fumes and to prevent excessive discharge through that portion of the outlet 91 in alignment with said discharge.

A suitable arrangement for disconnecting a lateral section 99 of the distributor from central section 98 is illustrated in detail in Fig. 9, and is of the telescoplng type including a supporting extension |02 on section 98 slidably fitting snugly into the end of section 99 and provided with. a peripheral flange |03a abutting against a similar ange |04a on the inner end of section 99 when the parts are in assembled position. Another arrangement is illustrated in Figs. 11 and 12, in which abutting ends of sections 98 and 99 are provided with registering diagonal peripheral flanges |04 connected at the top by hinge |05 provided with a removable pintle |06, the portion of the hinge connected to central section 98 being advantageously supported from frame 2| by bracket |01. Hinges |05 are located at opposite ends of the center portion 98 of the distributor in proper position to permit the lateral sections 99 to be swung upwardly without interference with other portions of the unit into substantially upright position and for thispurpose are advantageously located slightly to the rear of the truck body 20.

A' suitable arrangement is provided for introducing uniformly distributed powder or dust to the treated area, advantageously utilizing the recirculation' system for this purpose. In the form. illustrated and shown in detail in Fig. 5 the powder is stored in a suitable bin 24 provided with a hinged cover and discharging into worm casing ||2 which may be integral therewith, bin 24 and casing ||2 being mounted on frame 2|. Worm H3 rotatably mounted in passage ||4 through casing ||2 is operative to propel material passing from the interior of bin 24 along said passage into feed box I5 connected to the recirculation system and arranged to provide uniform feed of the powder to the current passing through said system. In the illustrated embodiment, feed box 5 extends around the outer half of the body section 84 of the return pipe which is cut away within the box to permit the powder discharged from passage ||4 above the center of section 88 to fall directly into the current passing through said section. 'I'he outer face of box ||5 is desirably provided with a removable face plate ||6 for inspection purposes, and to permit the introduction of a suitable container, for example, a bucket, to catch the dust discharged from the bin for a given travel of the truck while the blower is shut down. By Weighing this dust, the apparatus may be calibrated and adjusted to give the proper amount of discharge. A stirring wheel ||.1 may be mounted in bin 24 and rotated by engagement with worm 3 in knbwn manner. With this arrangement the powder .passes to blower "3 which assures thorough and uniform mixture of the powder with the reclrculating current of gas and the fumes carried thereby.

Suitable means is provided for driving worm ||3. In the illustrated embodiment worm shaft |30 is supported by journal |3| at the end of casing I2 and journal |32 mounted on the frame 2|, and is driven from drive shaft 6| by a changeable speed connection. In the illustrated arrangement three pulleys |33 of progressively decreasing diameter are fixed to shaft |30 in alignment with three pulleys |34 of progressively increasing diameter mounted on drive shaft all pairs of aligned pulleys having the same total diameter. Belt |35 may be placed around any selected pair :of aligned pulleys |33, |34 for driving shaft |30, the arrangement providing three different speeds of worm ||3 for the same speed of rotation of shaft 5|.

A suitable arrangement is provided for combining the nicotine with the powder. This is advantageously accomplished by intermingling the discharge from distributor 95 carrying the powder with the discharge from nozzles 19 carrying the vaporized nicotine. For this purpose nozzles 19 and discharge openings 91 of distributor 95 are arranged in parallel relationship and juxtaposition so that the streams of vapor and dust are intermingled immediately below the space between the nozzles and outlet and above the plant growth to be treated. It has been found that with this arrangement the powder will take up a substantial proportion of thenicotine and will then pass immediately to the plant growth, eliminating any opportunity for decomposition of the nicotine before it reaches the zone of effective action.

A modified arrangement for distributing the powder and combining it with the nicotine is disclosed in Fig. li, in which two transverse dis- -branch 91h, eachl branch consisting of a substantially continuous aperture passage or channel extending throughout the length ofV distribu-A tor 95a. The zone ||8 of the dust discharge from outlets 91a and 91h and the zone ||9 of the nicotine discharge from nozzles 19 are indicated diagrammatically in Fig. 4. Each distributor 95a Iis connected by an inwardly deflected central riser |20 to the rear end section 94 of feed pipe 93.

Under certain circumstances it is desirable to introduce the nicotine into the recirculation system, and when powder is employed to combine the nicotine and powder before discharge of the latter into the air. For this purpose suitable pipe connections from pipe are provided, discharging into the recirculation return pipe 84, feed pipe 93, or both. In the illustrated arrangement a branch pipe |22 extends from pipe 15 beyond the point of introduction of nicotine and ata point where the nicotine has been vaporized, and discharges through a suitable connection |23 into th front section 89 of return pipe 84 adjacent the inlet to blower 23. A suitable thermometer |24 may be mounted on pipe |22 adjacent its discharge end to permit observation of the pipe temperature and adjustment thereof in the manner already indicated. Another branch pipe |25 ,extends from pipe 15 desirably to a point beyond where the nicotine has been introduced 'and has been substantially vaporized, and dis- .charges through a suitable connection |26 into the feed system, preferably into the'rear end section 94 above the connection to distributor 95. Valves |21 in branch pipes |22 and |25, and in pi-pe 15 beyond the points of connection of said branch vpipes therewith, permit selective discharge of thenicotine to the recirculation feed Y pipe, the recirculation discharge pipe or the Vdistributor pipe 18, as well as any desired proportional distribution of the nicotine to some or all of said points. 'I'he valve system likewise permits regulation of the pressure in pipe 15 in the zone of introduction and vaporization of the nicotine. Branch pipes |22 and |25 are of course provided with suitable thermal insulating jackets 18 to maintain, the proper temperature for nicotine vaporization to the point of introduction of such vapor into the recirculating system.

A suitable temporary enclosure in the form of an apron or canopy covering the area undergoing treatment is mounted on the unit. For this purpose a suitable framework is provided, extending laterally from the unit to points beyond the ends of the distributing apparatus; and means for collapsing or withdrawing the portions of. the frame projecting substantially beyond the sides of the truck body is advantageously provided. In the illustrated embodiment this framework comprises a generally rectangular frame |36 formed of iron piping and including a front bar |31 supported from the truck platform 20 by hangers |38 and U-bolts |39 encircling bar |31 and mounted in a vertical series of holes in hangers |39 at the desired distance from the ground. Rear bar |40 of frame |36 is similarly mounted by means of U-bolts |4| (Figs. 1a, 2) at an adjustable height by U-bolts |4| mounted ina series of holes |42 in vertical supports |43 carried by the rear cross beam |44 of extension frame 90. Side bars |45 connect the outer ends of bars |31 and |40 and are rigidly attached thereto.

A collapsible arrangement is provided by forming front bar I 31 with a central section |46 engaged by bolts |39 and side sections |41 slidably mounted in section |46, rear bar |40 being similarlyformed with a central section |48 engaged by U-bolts |4| and side sections |49 slidably mounted in the ends of section |48. The frame is designed for convenient construction from ordinary piping with the ends of bars |31 and |40 connected to side bars |45 by Ls and the side sections |41, |49 slidably fitting in central sections |40,V |48. The side and central sections are detachably held in operative position as by cotter pins |50 extending through the piping of the respective side and central `sections at each point of connection.

Suitable means for supporting and bracing portions of the apparatus extending laterally beyond the truck, are provided. In the form described hanger rods |5| are detachably hooked at their ends through suitable eyes |52, mounted on the outer portions of rear bars |40, and through the upper parts of supports |43 located substantially above the level of thev bar |40 to provide suitable vertical support. The inner ends of rods |5| are connected by a tension strap |53 engag-v ing the upper parts of supports |43. Similar hanger rods |54 are detachably hooked at their ends through eyes |55 at the outer ends of' front bars |31 and through suitable holes in anges I 58 of the frame 2|, located substantially above the level of bar |31. The'frame |36 is also reinforced against the drag oi the canopy by brace rods |51 detachably engaging at their ends the end portions of front bar |31 and platform 20 at a point substantially in advance oi bar |31. Rods |5l, |54 and |51 are provided with suitable turn buckles |58 for convenience in providing accurate and adjustable tension. The portions of the distributing apparatus extending laterally beyond lll the lateral distributor pipe sections 82 and the lateral sections 06 of the powder distributor 95 are provided with hanger rods |62 hooked over support rod |59, which is mounted on front bar |3i by pivotal connection |60 and detachably held in placeon side bar by pin IBC.

A suitable canopy C enclosing the area under treatment is mounted on frame |36, and is formed of air-tight flexible material such as woven fabric impregnated or coated with a suitable elastic composition, usually a rubber compound. The canopy C comprises a front wall |65 suspended from front bar |31, side walls |66 suspended from side bars |45, a rear wall |61 suspended from rear bar |40 and extending therefrom downwardly and rearwardly, and a top wall |68 extending continuously between bars |31, |40 and |45 except where the top wall is necessarily cut away for portions of the unit and supports extending through the wall. Front, side, rear and top walls are continuously connected or juxtaposed along contiguous edges to form a substantially closed canopy extending to the ground and may be weighted along their lower edges in known manner to maintain contact with the ground and plant growth thereon. The bars forming frame |36 may be located in suitable pockets |69 formed in the margins of the canopy walls.

Suitable ,means for directing and regulating the flow of the recirculating current of gas beneath canopy C is provided. This includes an arrangement for directing toward the plant growth the insecticidal material discharged beneath the canopy. For this purpose a transverse-A fiexible baille or apron |10 (Figs. la, 2a) is suspended from the top wall |68 of the canopy and extends transversely substantially across the space between side walls |66 `and downwardly. from the top wall |66 for a sumcient distance to force the rearwardly traveling current of fumigant into contact with the plant growth. Apron |10 may be madel of material similar to the canopy C and is sulciently flexible to be'deflected rearwardly by engagement with such growth without danger to the same where necessary, being desirably provided with a flexible weight such as rope or chain |1| attached to the lower margin of apronv |10 and of proper weight to maintain said margin in vertical position or in engagement with plants passing thereunder.

A suitable arrangement for preventing the canopy C from obstructing suction inlets 85 is provided. In the form illustrated frames |12 are adjustably mounted by pivot bolts on supports |13 carried by cross-beam |44 and are located at the rear of each inlet 85. The frames may be held in any desired angular position as indicated in Fig. 6, and mayr yield under Yabnormal pressure to avoid canopy rupture.

A modified arrangement is indicated in Fig. 13, and comprises an adaptation of the construction already described to the treatment of plant growth in a stationary enclosure. In the embodiment shown, a tree |15 isfcovered by a suitable canopy l'EGi which may -be of material similar to that employed in canopy C. Canopy |16 completely encloses the vtreeand is closed at the bottom, as by holding the lower margin of the canopytightly against the ground by stones |11. The discharge end of feed pipe S3 is connected to a flexible tube |18 discharging through the upper part of canopy |16.- -A exible return l tube |19 is connected at oneY end with the space beneath canopy |16 toward the lower part of the canopy and desirably below the lower branches of the tree in the form disclosed, the other end of tube |19 connecting with the return pipe 84 in advance of powder feed box H5. In this embodiment means is provided for feeding the dust and nicotine when the truck is stationary. A simple arrangement comprises a hand crank |80 on worm shaft |30.

The nicotine employed with the described system is advantageously as nearly anhydrous as can be obtained in commercial practice, and generally consists of from 94 to 99% nicotine, the remainder consisting of resinous and other non-aqueous impurities. It is desirable to employ a product containing approximately 98% nicotine and less than 1% water, since this material may be produced commercially without resort to chemical treatment.

The nicotine is desirably combined with a hydrocarbon of lower boiling point than the nicotine, facilitating observation of the otherwise transparent fumes and providing protection against decomposition of the nicotine, especially when gasifled. Hydrocarbons suitable for this purpose, together with proportions and conditions of use, are set forth in Arnold Patent No. 2,120,225. The hydrocarbonis moreover, combined also with the dusting powder, and serves to improve the effectiveness of the resulting composition, particularly serving to increase the adhesiveness of the powder to the plants and insects, and when the nicotine fumes are used without the powder, the use of hydrocarbons as indicated is of primary importance.

When hydrated lime is employed as the dustlng powder, it should be of the neness generally employed for such purposes and should contain as low an uncombined water content as is feasible in commercial practice, preferably less than 1%. The nicotine concentration beneath the canopy C may be that set forth in Arnold Patent No. 2,120,225, but may be substantially increased from the concentration set forth therein, owing to the more economical operation provided by the recirculation system. 'I'he amount of dust supplied to saidspace may likewise be substantially higher than that employed in ordinary dusting operations because of the recovery of excess dust through the recirculation system.

Many features of the method of operation of the construction shown in Figs. 112.will be apparent from the foregoing description. After assembling the unit with the canopy and distributors in position, the feeding mechanism can be operated at will through clutch handle 61. The rate of nicotine feed with relation to the distance traveled by the truck may be determined empirically by diverting the nicotine into gauge 5|, andthe rate of feed adjusted by suitably rotating pump cap 5G. The preferred rate of powder feed may be selected by placing belt 35 on the appropriate pair of pulleys E33, i3d. Temperatures in the nicotine gas feed lines may be observed from thermometers 1T, EN, and acl- `iusted by shifting the engine spark and by varying the pressure in said lines through manipulating valves itil, the latter likewise regulating the points at which the nicotine gas is introduced into the recirculating system.

When the unit is properly adjusted the nicotine fumes are discharged beneath the forward portion of canopy C and promptly envelop plant growth beneath the canopy. The fumes travel rearwardly in a current passing through may be provided without waste.

`materials, plant lgrowth and fumigants.

and around the plant growth under apron |10 and thence to the rear of the space under canopy C. The gases and suspended material beneath the rear end of the canopy are drawn through suction inlets 85. This arrangement provides a certain amount of pressure adjacent the forward end of the canopy C, combating the tendency'of the outer air to leak beneath the canopy as the unit travels forward, and also provides a reduced pressure toward the rear of the canopy, opposing the tendency of the gases and material suspended therein to pass outwardly beneath the trailing end of said canopy.

Where the arrangement is employed to feed the nicotine simultaneously with a powder which combines therewith, the relative proportions of since the fumes themselves are eiective beneath canopy C while the nicotine carried by the powder continues its effectiveness after the canopy has passed and serves to complete-the destruction of parasites which may have been materially affected but not killed during treatment beneath the canopy.

The described arrangement is capable of flexible operation to suit various types of treating It may be operated to apply fumes alone by disconnecting belt |35, or to apply dust alone by discon necting belt 63. It moreover constitutes an apparatus for charging a suitable dusting powder with a liquid or gaseous parasiticidal material, or

concentration in a relatively short period, but also assures adequate dusting of all surfaces where desired since a substantial excess of dust Although the form illustrated discloses the current of fumigant as passing downwardly through the tree, this showing is not intended to be restrictive, since 'the system is obviously adapted to the provision oiga current passing through the plant growth in any fdesired path, including upward flow thereof. The feed mechanism may be operated when the truck is stationary by means of hand crank |80, though the truck motor may likewise be employed under proper conditions by jacking up wheel 56 so that it clears the ground. 'Either mode of operation may be used to feed either dust alone or nicotine and dust in the manner already described. In some cases the apparatus may be employed without a canopy, in which case, however, all the advantages of recirculation are lost, but substantially all other advantages are retained.

'I'he invention is especially advantageouswith gasied nicotine, but certain features are applicable to other methods of operation, especially plants.

when substances other than nicotine are employed.

While the invention has been more particularly described in connection with the application to the plants of a volatilizable parasiticide, or of such a parasiticide and a suitable carrier dustit is also highly advantageous when a preformed or natural parasiticide dust such as powdered derris root is to be applied alone, in which case the apparatus for supplying the volatilizable parasiticide such` as nicotine is put out of operation.

In such use of a parasiticidal dusting powder l the dust distributors are particularly important during the travel of the apparatus as they ensure 15 the complete covering of all parts of the plants,

-since each plant will be struck in two directions by two discharges of dust where only one distributor is used and by four discharges and from two angular directions as well as downward, when 20 two distributors are used, as will be clear from Fig. 4 of the drawings. The work done with the apparatus in pea fields has shown that using derris powder only the kill of aphis has been better than previously obtained by other methods and apparatus. y

While the preferred embodiment has been described, together with certain modifications, the invention is not limited thereto, since various modications may be made within the limits of the invention as indicated by the claims.

' What is claimed is:

1. 'I'he method of applying parasiticides to plants and the like, which comprises gasifying a volatilizable parasiticide, mixing it with exhaust gases, bringing the mixture intocontact with a ldusting powder suspended in gas, and applying 3. The method of applying nicotine parasiticides which comprises gasifying a mixture of substantially anhydrous nicotine and a hydrocarbon protective against nicotine decomposition having a boiling point not materially higher than that of the nicotine, combining the nicotine and hydrocarbon fumes with a suspension oi substantially anhydrous hydrated lime dusting powder in gas and applying the resultant powder in suspension;t to plant growth.

4Q The method of applying nicotine parasiticides which comprises suspending a dusting powder vin gas, contacting nicotine with the powder in suspension, applying the suspended powder andv nicotine to plant growth in an enclosure, 50 withdrawing gas from the enclosures, suspending additional powder in the withdrawn gas,

adding nicotine thereto and returning the gas carrying the suspended powder and nicotine to the point of application to plant growth.

5. The method of applying a parasiticide to fieldl plants beneath a traveling enclosure, which comprises introducing the parasiticide nely disseminated in a gaseous fluid, beneath the forward portion of the enclosure and withdrawing gaseous uid with any accompanying parasiticide from beneath the rearward portion oi the enclosure.

, 6. The method of applying a parasiticide to eld plants beneath a traveling enclosure, which comprises introducing the parasiticide nely dis- 75 seminated in a gaseous uid, beneath the forward portion of the enclosure, withdrawing gaseous fluid with any accompanying parasiticide from beneath the rearward portion of the enclosure,

. adding more parasiticide to the said withdrawn gaseous fluid and returning it to the forward portion of the enclosure during the travel of the enclosure.

'7. The method of fumigation of plant growth with fumigant applied beneath a traveling enclosure which comprises introducing a gas containing a iumigant beneath the forward portion of the enclosure and withdrawing gas from the rearward portion of the enclosure during travel. 8. The method of Afnmigation of plant growth with fumigant applied beneath a traveling enclosure which comprises introducing a gas contributor, each arranged to extend transversely at the rear of the vehicle, means on the vehicle for suspending the powder in a gas and feeding the suspension to the powder distributor, and means on the vehicle for gasifying the nicotine and feeding the resulting nicotine fumes to the nicotine distributor.

10. An apparatus for applying parasiticides toplants. comprising, in combination, an enclosure for the plants, means for introducing into the 4enclosure fumes-of a volatilizable parasiticide and a dusting powder in suspension in a gaseous fluid, and a recirculating system including means for withdrawing gaseous uid from the enclosure, with any parasiticidal material it may contain, means for supplying further parasiticidal material to said withdrawn gaseous fluid, and means for returning the said recharged gaseous -fluid to the -introducing means.

11. A fumigating apparatus comprising in combination an enclosure, means for introducing into the enclosure nicotine fumes and a gas suspension of a dusting powder coalesced with the nicotine, and a recirculation system including means for withdrawing gas from the enclosure, adding nicotine fumes and powder to the withdrawn gas and returning the gas to the introducing means.

12. Traveling fumigation apparatus comprising a traveling canopy enclosing the fumigation zone, and means for supplying fumigating material to the'canopy enclosure including means for withdrawing gas from the rearward portion of the enclosure and returning the gas to the forward portion of the enclosure.

13. Traveling fumigation apparatus comprising a vehicle and fumigating equipment mounted on the vehicle, including a canopy enclosing a ground area at the rear of the vehicle, means for introducing nicotine fumes beneath the forward portion of the canopy adjacent the vehicle, and means for withdrawing gas from beneath the rear portion of the canopy and returning said gas beneath the forward portion of the canopy.

14. Dusting apparatus comprising means for suspending a plant dusting powder in a gas, means for feeding the suspended powder to the space within an enclosure, and means for withdrawing gas from the enclosure and supplying it to the powder suspending means.

I15. Fumigating apparatus for the fumigation of horizontally extending plant growth comprising a canopy enclosing said growth and means for directing a gas current carrying fumigating material in a horizontal path in contact with said growth, comprising means for supplying gas and fumigating material to the canopy enclosure in a restricted zone, and means for withdrawing gas from the enclosure at a point horizontally spaced from the zone of gas supply and returning the Withdrawn gas to the supply means.

16. Apparatus for the traveling fumigation of horizontally extending plant growth comprising a canopy enclosing a portion of the plant growth, supply means including means for directing a gas current containing fumigating material in a horizontal path in contact with said growth including means for supplying gas and fumigating material to the forward portion of the canopy enclosure and means for withdrawing gas from the rearward portion of said enclosure and returning the withdrawn gas to the supply means; and means for conveying the canopy and'supply apparatus along the plant growth.

17. Fumigating apparatus comprising means for supplying gas carrying fumigating material in a restricted zone within an enclosure, means for withdrawing gas from the enclosure at a point spaced from the supply zone and returning the withdrawn gas to the supply means, and means for regulating the withdrawal of gas.

18. Fumigating apparatus comprising in combination a vehicle; a support on the vehicle; a fumigating unit mounted on the support including an internal combustion engine, a nicotine supply, a dusting powder supply, nicotine gasifying and feeding means including a distributor, an insulated engine exhaust pipe connected to the distributor. and means for introducing nicotine into the pipe; and a gas recirculation system including a blower, a return pipe connected to the blower inlet, a supply pipe connected to the blower inlet, a distributor into which the supply pipe discharges, located adjacent the nicotine distributor, and means for feeding dusting powder to the gas recirculation system.

ROBERT B. ARNOLD. 

